Abstract
The hippocampal cognitive map can reflect spatial and nonspatial task conditions by binding relevant aspects of experiences within a context. Sharp Wave Ripples (SWRs) are known as the most synchronous neural pattern during memory consolidation. Using a visual context associative learning paradigm, we look for the temporal relationship between the incidence of hippocampal SWRs and collected targets across trials. This study investigates how activity in the human hippocampus changes according to different contextual conditions in the same space. We anticipate that learning the task will increase the likelihood of recording these task-related activities. As part of Western University's epilepsy program, participants were implanted with depth intracranial electrodes using StereoElectroEncephaloGraphy (SEEG) for preoperative evaluation. Participants navigated the circular maze's boundaries while collecting treasure boxes and earning points. Contextual information was displayed on the maze walls and then coloured targets were displayed in the decision zone after leaving the navigation zone. We developed our algorithm for detecting SWRs and synchronized it with a behavioural state space model. The 35th trial of 42 was considered the initial learning trial, and 0.99% of the performance was correct from there. We determined that 86% of SWRs were detected before the initiation point across four implanted electrodes in the right and left hippocampus. When the player reached 30% of the task's total duration, the rate of ripples was at its highest. The rate of normalized events was about 10 times greater for the significant change in incorrect vs correct trials. Preliminary findings from one patient recording indicate that the rate of SWRs increases as learning occurs. Two specific increases in SWRs were detected in both successful and unsuccessful trials. Moreover, the significant change in the rate of ripples was associated with the unsuccessful trial, illustrating the importance of failed trials during the learning process.